Abstract:
Background: Visceral Leishmaniasis (VL) is a disseminated protozoan infection caused by
Leishmania donovani parasites which affects almost half a million persons annually. Most of
these are from the Indian sub-continent, East Africa and Brazil. In this study, we aimed to
determine the levels of antibodies and cytokines in visceral leishmaniasis patients at the time of
diagnosis, during treatment at different time points and after treatment so as to examine
associations with parasitaemia and clinical states (prognosis) of patients.
Methods: A prospective study enrolling a total of 48 active Visceral Leishmaniasis (VL) patients
were evaluated before treatment, during treatment at different time point and follow-up after
treatment up-to three month to determine their serum cytokine concentration, antibody levels,
splenic aspirate, laboratory and clinical parameters.
Results: Statistically significant differences in the absolute counts of WBC, Platelet and
measurement of Hemoglobin (Hb) were observed before treatment at day 0 compared to during
treatment at day 7, 14, 18, 18(EOT) and 30(EOT) days (P < 0.001). Measurement of serum
cytokine showed that VL patients had elevated levels of circulating IL-10, IFN-γ, and TGFΒ
regardless of microscopic parasite load and levels of antibody. The observed highly elevated
level of IL-10 cytokine in serum was sharply decreased after start of treatment within seven days.
High level of anti-leishmania antibodies was present in all VL patients regardless of spleen
aspirate microscopic parasite grade before treatment and at different time during treatment.
However; a significant decrease of antibody level observed at 120 days post treatment with
median O.D. values of 1.47. IL-2 serum levels were below detection limit in VL patients.
Conclusions: In conclusion, the present results suggest that cytokines can be used as markers of
disease in epidemiological studies to distinguish between the different clinical forms of VL. In
addition, measuring circulating cytokines concentration could be used as criteria for cure in
combination with other clinical evaluations and their usefulness should be confirmed in
investigations conducted in other endemic areas.
